The Invader Fractal is a region of space filled recursively with 15
bit combinatoric objects affectionately called Invaders. Look carefully
and you might see your childhood experiences with computers unfold
in the maze of icons.

CLICK
an Invader to destroy it. The empty space will then be refilled with
more invaders. This is the strategy of the invaders.

figure
a. a few of my favorites.

Hundreds and even thousands of Invaders are arranged in this computational
construct so that eventually the space is filled completely. The space
filling algorithm used here is similar to the one used in the Emotion
Fractal.

figure b. the
internal bitwise representation of the Invader is only 15 bits, while
its graphic appearance is 25 bits.

The Invader itself occupies a 5 x 5 grid of blocks (25 bits). Internally,
the Invader is represented by a 3 x 5 grid (15 bits) because it
is also horizontally symmetric. The left side of the Invader simple
draws identical to the right.

If we iterate through all possible combinations of lighting bits
in a 3x5 grid, and eliminate no invaders on the basis of shifted
similarity, there are 32,768 (2 to the 15th power) unique Invaders.

figure c. 1,936
unique Invaders, a mere 6% of all possible Invaders.

What is most interesting in this work is the way in which a very small
amount of information (15 bits) can be represented graphically, so
that it can be more easily remembered by the human observer.